This application claims the benefit of the Korean Application No. P2002-47801 filed on Aug. 13, 2002, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a clothes dryer, and more particularly, to a clothes dryer in which a hot blast is used to dry a dry object.
2. Description of the Related Art
Generally, a clothes dryer is an apparatus for automatically drying a dry object after a washing process. There are two different types of clothes dryers: a discharge type clothes dryer in which an external air is introduced to perform a dry process and a condensation type clothes dryer in which an internal air is circulated for the dry process and a moisture is condensed to a waterdrop to be discharged.
A discharge type clothes dryer of the prior art will be described below in reference to the accompanying drawings.
Referring to FIGS. 1 and 2, a prior art clothes dryer of the discharge type comprises a cabinet 1, a drum 3, a driving device, a heater 5, a suction duct 7, an exhaust duct 15, a lint duct 8, and a blast fan 13.
At this time, a door 2 is provided on the front side of the cabinet 1. The drum 3 is rotatably provided in the cabinet 1 and a plurality of tumbling ribs 4 are provided on the inner circumferential face of the drum 3. The driving device being provided to provide a rotating force to the drum 3 includes a motor 10, a driving pulley 11 coupled to the motor 10, and a belt 12 being connected to the driving pully 11 and winding the outer circumferential face of the drum 3. When the driving device is operated, the driving pulley 11 is rotated by the rotation of the motor 10, thereby rotating the belt 12 and the drum 3 as well.
As shown in FIG. 1, the heater 5 is provided in the suction duct 7 to produce a hot blast by heating sucked air to a high temperature. The suction duct 7 communicating with a rear opening of the drum 3 sucks external air through its one end and guides a hot blast generated by the heater 5 into the drum 3. The exhaust duct 15 communicates with an outside of the cabinet 1. The lint duct 8 is provided to respectively communicate with a front opening of the drum 3 and the exhaust duct 15 so as to guide humid air after a dry process to the exhaust duct 15. A filter 14 is provided on an opening of the lint duct 8 to filter 14 off lint particles from the air being exhausted from the drum 3. The blast fan 13 being provided on the rear side of the lint duct 8 exhausts the humid air being guided to the exhaust duct 15 by generating a blast force.
A drying process of a clothes dryer according to the prior art will be described below.
First, the dry object is put into the drum 3. Then, as a dry process is started, the motor 10 is operated and the drum 3 is rotated. According to this, the heater 5 and the blast fan 13 are also operated. As shown in FIG. 2, as the blast fan 13 starts operating, external air is sucked into the cabinet 1 and heated by the heater 5. The heated air becomes a hot blast and is introduced into the drum 3 being rotating. The hot blast in the drum 3 evaporates the moisture of the dry object. In this way, the hot blast becomes humid air of a low temperature being exhausted to the exterior through the lint duct 8 and exhaust duct 15.
However, the clothes dryer according to the prior art has some problems or disadvantages. In the clothes dryer according to the prior art, a hot blast flows in one direction to the drum 3, from a rear side to a front side, to perform a dry process. Accordingly, the temperature difference between a hot blast inlet on the rear side of the drum 3 and a hot blast outlet on the front side of the drum 3 becomes larger. For that reason, in the drum 3, the dry object on the rear side is rapidly dried while the dry object on the front side is very slowly dried. Accordingly, the dry process is performed unevenly depending on the position inside the drum 3 and occasionally, in the worst case, the dry object may be damaged.
To overcome such a problem as the uneven dry process of the prior art, various operation control methods have been introduced, in which a cooling process is added during the dry process. However, the operation control method is not enough to fundamentally work out the problem and also can result in other problems such as increased dry processing time and low energy efficiency.
Accordingly, the present invention is directed to a clothes dryer that substantially obviates one or more problems due to limitations and disadvantages of the prior art.
An object of the present invention is to provide a clothes dryer that prevents an uneven dry phenomenon and possible damage of a dry object and reduces dry processing time.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a clothes dryer of the present invention comprising a cabinet, a drum, first and second connecting ducts, a heating duct, an exhaust duct, and first and second flow passage control devices. The drum is rotatably provided in the cabinet. The first connecting duct is connected with a rear side of the drum to communicate with an inside space of the drum and the second connecting duct is connected with a front side of the drum to communicate with the inside space of the drum. The heating duct provides air to the drum. The exhaust duct exhausts the air which passes through the drum to an outside of the cabinet. The first flow passage control device communicates the heating duct with the first connecting duct or with the second connecting duct selectively. The second flow passage control device communicates the exhaust duct with the first connecting duct or with the second connecting duct selectively.
A heater for heating the air is provided in the heating duct. A blast fan for circulating the air is provided in the exhaust duct.
The first and second flow passage control devices include solenoid valves being operated according to a control signal of a controller.
Also, a first guide duct is provided to communicate the heating duct with the first and the second connecting duct. The first flow passage control device is provided in the part where the first guide duct and the heating duct communicate with each other.
Additionally, a second guide duct is provided to communicate the exhaust duct with the first and the second connecting duct. The second flow passage control device is provided in the part where the second guide duct and the exhaust duct communicate with each other.
At this instance, when the first flow passage control device is operated to communicate the heating duct with the first connecting duct, the second flow passage control device is operated to communicate the exhaust duct with the second connecting duct. When the first flow passage control device is operated to communicate the heating duct with the second connecting duct, the second flow passage control device is operated to communicate the exhaust duct with the first connecting duct.
Also, a filtering device is provided for filtering the air. The filtering device includes first and second filters. The first filter is provided in the part where the first connecting duct and the second guide duct communicate with each other. The second filter is provided in the part where the second connecting duct and the second guide duct communicate with each other. A third filter is additionally provided in the heating duct.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.